Schall R, Müller F O, Hundt H K, Duursema L, Groenewoud G, Van Dyk M, Van Schalkwyk A M
FARMOVS Institute for Clinical Pharmacology and Drug Development, Department of Pharmacology, University of the Orange Free State, Bloemfontein, Republic of South Africa.
Biopharm Drug Dispos. 1994 Aug;15(6):493-503. doi: 10.1002/bdd.2510150607.
Four controlled-release nifedipine products were investigated in two clinical studies. In study 1, 22 healthy male volunteers took part in an open, multiple-dose, randomized, crossover study to determine the relative bioavailability of two 10 mg controlled-release nifedipine tablets (Adalat Retard, Bayer), administered 12 hourly, and one 20 mg controlled-release nifedipine tablet (Adalat Retard, Bayer) administered 12 hourly. In study 2, 24 healthy male volunteers took part in an open, multiple-dose, randomized, three-period, crossover study to determine the relative bioavailability of (i) two 30 mg nifedipine gastro-intestinal therapeutic system (GITS) tablets (Adalat XL, Bayer) administered once daily; (ii) one 60 mg nifedipine GITS tablet (Adalat XL, Bayer) administered once daily; and (iii) one 20 mg plus one 10 mg nifedipine controlled-release tablet (Adalat Retard, Bayer), administered 12 hourly. In both studies detailed pharmacokinetic data, in particular with respect to the controlled-release characteristics of the different formulations, were collected. Results of both studies indicate that all nifedipine products investigated are bioequivalent with respect to the extent of absorption of nifedipine. The nifedipine GITS products (Adalat XL) have better controlled-release properties than the Adalat Retard product, and are suitable for once-a-day administration.
在两项临床研究中对四种硝苯地平控释制剂进行了调查。在研究1中，22名健康男性志愿者参与了一项开放、多剂量、随机交叉研究，以确定两种每12小时服用一次的10毫克硝苯地平控释片（拜耳公司的Adalat Retard）和一种每12小时服用一次的20毫克硝苯地平控释片（拜耳公司的Adalat Retard）的相对生物利用度。在研究2中，24名健康男性志愿者参与了一项开放、多剂量、随机、三阶段交叉研究，以确定以下制剂的相对生物利用度：（i）两种每日服用一次的30毫克硝苯地平胃肠道治疗系统（GITS）片（拜耳公司的Adalat XL）；（ii）一种每日服用一次的60毫克硝苯地平GITS片（拜耳公司的Adalat XL）；以及（iii）一种每12小时服用一次的20毫克加10毫克硝苯地平控释片（拜耳公司的Adalat Retard）。在两项研究中均收集了详细的药代动力学数据，尤其是关于不同制剂控释特性的数据。两项研究的结果均表明，所研究的所有硝苯地平制剂在硝苯地平的吸收程度方面具有生物等效性。硝苯地平GITS制剂（Adalat XL）比Adalat Retard制剂具有更好的控释特性，适合每日一次给药。
